This invention relates to a perpendicular type magnetic recording member and a manufacturing method therefor. Recently, a perpendicular type magnetic recording system and an optical magnetic recording system have attracted attention as new magnetic recording systems for high density recording. A magnetic film for these recording systems has to be a so-called perpendicular deposition magnetic film which has a magnetic anisotropy in the direction perpendicular to the plane of the film and has to satisfy the conditions of Ku.perp..gtoreq.2.pi.Ms.sup.2, Hc.perp.&gt;Hc.parallel. and Br.perp.&gt;Br.parallel..
Co is known to have a large magneto crystalline anisotropy in the c axial direction of a hcp structure thereof. For obtaining a perpendicular deposition magnetic film by making use of the magnetic anisotropy of Co, it is necessary to satisfy the requirements: (1) that the direction of the c axis thereof is substantially perpendicular to the plane of the film and (2) that the crystal magnetic anisotropy energy Ku is larger than an energy of diamagnetic field 2.pi.Ms.sup.2 generated in the direction perpendicular to the plane of the film. However, the Co film is large in the value of a saturation magnetization Ms, and therefore does not meet the foregoing requirement (2), so that a perpendicular deposition magnetic film cannot be made from Co.
There has also been known, as one of the perpendicular-incidence deposition magnetic films, a Co--Cr system thin film. This film has been made by an evaporation process. However, the evaporation process is defective in that the vapor pressure of Co and Cr are largely different from each other, and consequently it is difficult to keep a uniform Co--Cr composition ratio for a long period of time during manufacturing of the magnetic film thereof. Also, a uniform magnetic film of a Co--Cr having a perpendicular magnetic property can be obtained only when its evaporation deposition onto a substrate is carried out when the substrate is heated to 200.degree.-300.degree. C. In other words, the perpendicular-incidence deposition magnetic film cannot be obtained when the substrate is not heated. However, such heating results in curling of a tape-shaped substrate and warping of a substrate of a floppy disk. In order to prevent this, a heat resisting substrate has to be used, resulting in an increase in production cost.